The Microscope - Volume 58, Second Quarter 2010
IN THIS ISSUE:
On the cover: A scanning electron microscope image of a radiolarian, an ocean-dwelling protozoan, which was colored using the brush tool in Adobe Photoshop. See Tricks of the Trade: Quick Coloring for SEM Images – Method 2: Photoshop Brush by Sebastian B. Sparenga.
Editorial: Faithfully Serving Science
The Microscope. 58 (2), p ii
Excerpt: There is a bookshelf here at McCrone Research Institute packed tightly with nearly every issue of The Microscope since its inception in 1937 – long before McRI founder Dr. Walter C. McCrone took the journal under his wing in 1962. With 73 years of printed matter, the shelf of journals is a treasure-trove of microscopy information. Flipping through the pages of older issues, it’s fascinating and fun to read about the research, techniques and instrumentation that emerged from microscopists’ labs in decades past. Full article (PDF)
Asbestos Fiber Counting by Different Optical Contrast Techniques
Anthony A. Havics
The Microscope. 58 (2), pp 51-62
Abstract: Fiber counting of asbestos using light microscopy has traditionally been performed using phase contrast microscopy (PCM) techniques. The use of phase contrast for counting has several weaknesses, including difficulties with fiber detection and overlapping diffraction patterns causing the appearance of “false” fibers or masking fibers. It is, however, a significant improvement over ordinary brightfield microscopy. The purpose of this study was to assess the use of two other contrast techniques, Hoffman modulation contrast (HMC) and Nomarski differential interference contrast (DIC). Samples of three fiber types, chrysotile, amosite, and man-made mineral fibers (MMMF) were used for this evaluation. DIC faired poorly in general and HMC faired reasonably well. The differences can be explained by the general aspects of contrast production in reference to phase detection and imaging of each method. Full article (PDF)
Visual Estimation in the Analysis of Surface Particulate by Microscopy
J.R. Millette and W.L. Turner, Jr.
The Microscope. 58 (2), pp 65-68
Abstract: Visual estimation is an important instrument in determining the relative amounts of different classes of particles present in surface samples. The visual estimates are semi-quantitative determinations that are used with polarized light microscopy (PLM), and occasionally electron microscopy, for particle characterization. A number of representative comparison charts showing areas covered by different particle densities have been published and are used by analysts to calibrate their visual estimates. A test of trained analysts, who calibrated their visual estimates with representative comparison charts and inter-analyst sample studies, showed a relative standard error for the procedure of approximately 30%. This value compared well with the inter-laboratory testing of laboratories using three semi-quantitative visual estimate procedures on asbestos bulk samples. Full article (PDF)
Critical Focus: Inventing Life or Reality?
Brian J. Ford
The Microscope. 58 (2) pp 69-77
Excerpt: If there’s a subject of conversation for microscopists this summer it must be the synthesized cell. “Artificial life” has reportedly been created in a test tube by Dr. J. Craig Venter, that archvillain or inspired genius, depending on where you stand. The newspapers are reporting that Venter has created synthetic cells. Radio news is calling this as astonishing as splitting the atom. Science magazines are professing that this momentous development will allow us to create microbes that could perform miracles, like digesting the BP oil spill in the Gulf of Mexico. And television is proclaiming that we could even create – think of this! – entirely new species. Full article (PDF)
Tricks of the Trade: Quick Coloring for SEM Images – Method 2: Photoshop Brush
Sebastian B. Sparenga
The Microscope. 58 (2), pp 79-80
Excerpt: In the last issue of The Microscope, I explained the Hue/Saturation method in Adobe Photoshop (PS) as one way to quickly color gray SEM images. In this issue, I’ll show you how to achieve the same quality results by coloring images with Photoshop’s Brush tool (also known as the paintbrush). I used PS 6.0, but the same steps apply to newer versions of the program. Photoshop Elements may also be used but with a slightly different series of steps. Full article (PDF)
Microspectrophotometry (MSP) of Blood – An Update
Larry K. Peterson
The Microscope. 58 (2), pp 81-84. Originally published online in the Journal of American Society of Trace Evidence Examiners, Vol. 1, No. 1, June 2010 (www.asteetrace.org).
Abstract: Microscopic-sized particles of suspected blood that is too small for classical serological testing can be encountered in forensic samples such as its presence on fiber and hair surfaces, and as trace residues on larger objects. These samples may be of probative value, and the classification of a material as blood may promote subsequent DNA typing. Microscopy and microspectrophotometry (MSP) are instrumental methods used to identify trace material as blood. Spectral absorbencies of blood in the visible and ultraviolet ranges, and effects of aging are discussed. Full article (PDF)
Book Review: A Muddled Look at Medical Imaging
Biomedical Optical Imaging (Oxford University Press), edited by James G. Fujimoto and Daniel L. Farkas
Review by Steven Ruzin
The Microscope. 58 (2), pp 85-86
Excerpt: Published in 2009, Biomedical Optical Imaging is a timely reference book for advanced microscopists and diagnostic imaging specialists. The coverage is thorough, and except for a few chapters, it is targeted to an audience with a high level of expertise. This is not a beginner’s book but an in-depth reference text for those wishing to understand highly advanced optical techniques for (medical) research and/or optical instrument design. This quality – advanced optical plus advanced diagnostics – is perhaps its major flaw but not the only one. Full article (PDF)
The Microscope Past: 40 Years Ago – Glycol Methacrylate, an Embedding Medium to Study the Ultrastructure of Cotton Treated with Swelling Agents
S.M. Betrabet and M.L. Rollins
The Microscope. 58 (2), pp 87-91. Originally published in The Microscope, Vol. 18, No. 3, 1970.
Abstract: Glycol methacrylate, a water-soluble monomer, was used for embedding cotton swollen in sodium hydroxide solution, and the potential of this medium in the study of the ultrastructure of the swollen fiber has been indicated by comparing the results with those obtained by the conventional layer-expansion technique employing methyl and butyl methacrylates. Full article (PDF)
Copyright © 2010 Microscope Publications, Division of McCrone Research Institute. All rights reserved.